Can magneto-transport properties provide insight into the functional groups in semiconducting MXenes?

TL;DR

This study uses theoretical calculations to analyze how magneto-transport properties, specifically the Hall scattering factor, can reveal the presence of different functional groups in semiconducting MXenes, aiding surface group identification.

Contribution

It demonstrates that Hall factor variations in MXenes are significant and can be used as a novel method for identifying surface functional groups.

Findings

Sc2CF2 has a Hall factor of 2.49 at certain carrier concentrations.

Sc2CO2 exhibits a Hall factor around 0.5.

Sc2C(OH)2 achieves an ideal Hall factor of 1.

Abstract

The Hall scattering factor of Sc2CF2, Sc2CO2 and Sc2C(OH)2 is calculated using Rode's iterative approach by solving the Boltzmann transport equation. This is carried out in conjunction with calculations based on density functional theory. The electrical transport in Sc2CF2, Sc2CO2, and Sc2C(OH)2 is modelled by accounting for both elastic (acoustic and piezoelectric) and inelastic (polar optical phonon) scattering. Polar optical phonon (POP) scattering is the most significant mechanism in these MXenes. We observe that there is a window of carrier concentration where Hall factor acts dramatically; Sc2CF2 obtains an incredible high value of 2.49 while Sc2CO2 achieves a very small value of approximately 0.5, and Sc2C(OH)2 achieves the so called ideal value of 1. We propose in this paper that such Hall factor behaviour has significant promise in the field of surface group identification in MXenes, an issue that has long baffled researchers.